Method for delasting footwear



y 1968 R. A. SPENCE 3,381,324

METHOD FOR DELASTING FOOTWEAR Filed May 7. 1965 5 Sheets-Sheet 1 ROBERTA. .S'PE/VCE INVENTOR ATTORNEYS May 7, 1968 Filed May 7. 1965 R. A. SPENCE METHOD FOR DELLA STING FOOTWEAR 5 Sheets-Sheet s ROBERTA. .SPENCE INVENTOR ATTORNEYS R. A. SPENCE METHOD FOR DE LASTING FOOTWEAR May 7, 1968 5 Sheets-Sheet 4 Filed May 7, 1965 ROBERT A. .SPENCE INVENTOR M 1,94, Y A i f-z iii FIG. 9.

ATTORNEYS United States Patent 3,381,324 METHOD FOR DELASTING FOOTWEAR Robert A. Spence, Lincoln, Mass., assignor to Rain Corporation, Brookline, Mass, a corporation of Massachusetts Filed May '7, 1.965, Ser. No. 453,933 16 Claims. (Cl. 12-142) ABSTRAUT OF THE DISCLOSURE A method of separating footwear from a last by the application of pressure to exterior portions of the footwear While introducing a charge of fluid under pressure between the last bottom and footwear interior. This application of exterior pressure restrains the footwear from expanding during removal of the last with a resultant reduction in the loss of fluid pressure by leakage between the last and footwear interior.

T his invention generally relates to footwear manufacture and more particularly to an improved method for removing footwear from a last.

Facilitated removal of footwear, such as an assembled shoe, from a last has been an unattained desideratum in the shoe industry for a long time. Past delasting procedures were normally accomplished manually requiring considerable effort, particularly When a shoe had been pulled tightly over and around the last during the lasting operation.

Various procedures have been devised to assist the operator in separating a last from a shoe, one such procedure employing pneumatic pressure introduced between the last and the shoe to initially separate the same as more fully disclosed in US. patents, No. 3,106,730 and No. 3,107,354, concurrently issued on Oct. 15, 1963. While this pneumatic delasting procedure represents a significant advancement toward a facilitated delasting procedure, it has at times required supplemental manual effort in initially scparating the shoe from the last thus reducing the etficiency of the operation. This inefiiciency has been found to stem from leakage or loss of the pneumatic pressure between the shoe and the last.

Accordingly, it is an object of the present invention to provide an improved method for removing a shoe from a last by pneumatic pressure but which overcome the aforedescribed problems to provide a delasting operation which is highly efiicient.

A further object of the present invention is to provide a method for delasting a shoe by pneumatic pressure or the like, loss of which between the shoe and last is restricted to produce an improved delasting operation requiring no manual effort to initially separate the shoe from the last.

Other obiects and the entire scope of the present invention will become apparent from the following description and by reference to the accompanying drawings wherein like numerals refer to similar parts throughout and in which:

FIGURE 1 is a perspective view taken from the front left side of an apparatus constructed in accordance with the present invention;

FIGURE 2 is a partial perspective view of the apparatus illustrated in FIGURE 1 showing a shoe positioned for separation from a last;

FIGURE 3 is a partial perspective view taken from the front of the apparatus illustrated in FIGURE 2 during the clamping cycle of operation;

FIGURE 4 is a partial perspective view taken from the right side of the apparatus illustrated in FIGURE 3;

Patented May 7, 1968 ice FIGURE 5 is a partial perspective view taken from above the apparatus illustrated in FIGURE 3;

FIGURE 6 is a partial perspective view taken from the right side of the apparatus illustrated in FIGURE 5 during the cycle of operation where the shoe and last are separated;

FIGURE 7 is an enlarged fragmental plan view of the clamping assembly illustrated in FIGURE 6;

FIGURE 8 is an enlarged cross-sectional view taken along lines 88 of FIGURE 7;

FIGURE 9 is an enlarged fragmental elevation and view of the clamping mechanism illustrated in FIGURE 7;

FIGURE 10 is a schematic diagram of the pneumatic circuitry employed with the illustrated apparatus;

FIGURE 11 is a schematic diagram of the electrical circuitry employed with the illustrated apparatus; and

FIGURE 12 is a diagram illustrating the sequence of operation performed by the apparatus.

SUMMARY OF OPERATION Referring now to the drawings, and more particularly to FIGURES l to 6, a lasted shoe generally identified by the numeral In is mounted on a last supporting heel pin 50 located in the delasting station of the machine. Loading of the lasted shoe serves to actuate the electrical control circuit of the apparatus generally designated by the numeral 220, which in turn regulates operation of the pneumatic power station 200 and associated mechanical linkages causing the oppositely disposed clamping assemblies 64 and 66 to move into cooperative engagement with the contoured sides of the lasted shoe Ill in order to effect a pneumatic seal for restricting leakage of air during the pneumatic delasting operation more fully described in US. Patents No. 3,106,730 and No. 3,107,354 concurrently granted on Oct. 15, 1963, as well as Reissue Patent No. 25,529 granted Mar. 3, 1964, the disclosures of which are incorporated herein as a part hereof by reference. While air is being injected under pressure between the interior of tne lasted shoe 10 and bottom portion of the last 39, a pneumatic seal is formed between the last and related interior sides of the shoe due to the external pres sure beins applied by the clamping assemblies 64 and 66. By substantially reducing air leakage, a significant increase of pneumatic pressure is obtained within the lasted shoe during the delasting operation.

As the internal force of the pneumatic pressure increases in magnitude, the heel portion of the lasted shoe is urged upwardly relative to the heel portion 32 of the last in the manner illustrated in FIGURE 6 without destroying the established pneumatic seal due to the associated movement of the rear pressure pads 74 and 78 carried by the respective clampim assemblies 64 and 66. Upon completion of the delasting operation, the electrical control circuit will automatically interrupt any further injection of compressed air as well as reactivate the pneumatic power station 200 to retract the clamping assemblies 64 and 66 so that the operator can break the last in a conventional manner and remove the shoe. After the last has been withdrawn from the delasting station 160, the electrical control circuit is automatically reset for initiation of another cycle of operation.

Whenever desired, two of these units can be utilized in a dual installation to permit the simultaneous delasting of a shoe in one section while unloading a previously delasted shoe from the other section.

GENERAL DESCRIPTION Referring now more specifically to the apparatus illustrated in FIGURES 1 through 9, the tubular last supporting heel pin 59 is adjustably supported on a telescoping standard 52 which includes an inner tubular member 82 slidably mounted within an outer tubular casing 84 mounted on deck plate 54 which in turn is supported on the frame 56 of the machine. The inner tube 82 and supporting heel pin 50 may be vertically adjusted for height with respect to the outer tube 84 by means of set screw 86. The lower end 88 of the inner tube 82 is connected to a suitable supply of compressed air 230, as illustrated diagrammatically in FIGURE to provide a pneumatic passageway for the air extending through the inner tube 82 and associated heel pin 50.

The frame 56 of the machine contains a suitable structural support for the deck plate 54, delasting station 100, pneumatic power station 200 and electrical control section 220. As shown in FIGURE 1, the pneumatic station 200 includes an air operated cylinder 90 carrying a reciprocating piston rod 91 which supports a cross-head bar 92. The cross-head bar 92 in turn is pivotally interconnected at each end wit-h push rods 94 and 96 which contain universally movable swivel rod ends 104. and 186 at their respective upper ends (FIGURE 3). A clamping assembly located adjacent delasting station 180 includes a left clamp arm 68 and right clamp arm 70 which are independently mounted at one end on respective pivot pins 108 and 110 carried by related bearing supports 112 and 114, as shown in FIGURES 1 and 2. The swivel rod ends 104 and 106 are pivotally interconnected to the respective lower leg portions of arms 68 and 70 in such a manner that actuation of the compressed air cylinder 90 causes the reciprocating piston rod 91 and associated crosshead bar 92 to move upwardly thereby rotating arm 68 in a clockwise direction about pin 108 and arm 70 in a counterclockwise direction about pin 110, as viewed in FIGURE 3.

Mounted adjacent the respective ends of the upwardly extending leg portions of left clamp arm 68 and right clamp arm 70 are the left and right clamping mechanisms 64 and 66 which contain a series of pivotally interconnected plates disposed pyramidly to support pressure pads 72, 74, 76 and 78, mechanisms 64 and 66 are adjustably mounted on arms 68 and 70 by means of interlocked mounting plates 116 and 118 which are arranged to support hinge blocks 120 and 122, respectively. In turn, hinge blocks 120 and 122 support associated hinge block pins 124 and 126 on which left and right trunnion blocks 128 and 130 are pivotally mounted. Adjustably mounted on the forward face of trunnion blocks 128 and 130, are left and right pad mounting blocks 132 and 134 to which are fixed hinges 140 and 141 that support left and right front pad assemblies generally indicated by numerals 136 and 138, respectively. Hinges 140 and 141 support the left and right front intermediate plates 142 and 144 that carry front and rear hinges 146 and 148 which in turn support left and right front forward and rear pressure blocks 150, 152, 154 and 156 of the left and right front pad assemblies 136 and 138, respectively.

Referring now to FIGURES 5, 7, 8 and 9, pressure blocks 150, 152, 154 and 156 present contoured faces toward the shoe which are alternately convex and concave in cross-section. Left and right hinge arms 162 and 164 are pivotally mounted on the left and right trunnion pins 166 and 168 within a slot 166 located in trunnion blocks 128 and 130, respectively. Stop bars 170 are affixed to the upper surfaces of the left and right hinge arms 162 and 164 to prevent the same from dropping downwardly in slots 160 formed in trunnion blocks 128 and 130. The stops 170, however, permit left and right hinge arms 162 and 164. to rotate freely upwardly on left and right trunnion pins 166 and 168, respectively. Projecting rearwardly from the vertical faces of left and right trunnion blocks 128 and 130 are left and right roll car followers 172 and 174 which contact the respective outward vertical faces of hinge arms 162 and 164 to take up any outwardly directed thrust force. Mounted on the inward rear vertical faces of the left and right hinge arms 162 and 164 are lhinges 176 which carry the vertical left and right rear intermediate plates 178 and 180. Mounted on the inward face of each rear intermediate plates 178 and 180 are a related pair of hinges 182, each supporting a separate pressure block. Thus, left rear inside pressure block 184, left rear outside pressure block 186, right rear inside pressure block 188, and right rear outside pressure block 190 are individually supported by a related hinge 182 which in turn is supported by either the left or right rear intermediate plates 178 and 180. Coil springs 194 are affixed to the adjacent vertical outside surfaces of intermediate plates 142 and 178 in order to maintain their respective alignment when the left clamp mechanism 64 is in the open retracted position. A similar coil spring is attached to the right hand intermediate plates 144 and 180 to preserve their relative alignment when the right clamp mechanism 66 is in the open retracted position.

Affixed to the outer extremities of the inside surfaces of the eight pressure blocks are four pressure pads which are preferably of foam rubber. Left front pressure pad 72 is carried by pressure blocks 150 and 152, while the left rear pressure pad 74 is carried by pressure blocks 184 and 186. Right front pressure pad 76 is carried by pressure blocks 154 and 156 while the right rear pressure pad 78 is carried by pressure blocks 188 and 190. The left front pad assembly 136 may be adjusted vertically by means of the bolt fasteners 133 passing through an elongated slot 135 in left pad mounting block 132 and received in related trunnion block 128. Similarly the right front pad assembly 138 may be adjusted vertically by the fasteners 133 located between the right pad mounting block 134 and the right trunnion block 130. The left rear pad assembly 206 may be rotated upwardly about the left trunnion pin 166, causing coil spring 194 to flex while maintaining the relative longitudinal alignment between intermediate plates 142 and 178 in the open retracted position of the left clamp mechanism 64. Similarly the right rear pad assembly may be rotated upwardly about the right trunnion pin 168, flexing spring 194 While maintaining the relative longitudinal alignment between intermediate plates 144 and 180 when the right clamp mechanism 66 is in the open retracted position.

As illustrated in FIGURES 3 and 11, a load sensing microswitch 58 is mounted on a vertically adjustable microswitch support 210 secured to deck plate 54. Load sensing microswitch 58 is normally open and mechanically actuated by a load sensing microswitch rod 212 which is adjusted so that microswitch 58 will close and complete an electrical actuating circuit when the rod tip 214, located immediately in front of the heel pin is depressed downwardly by last 32. Another trigger microswitch 60, as illustrated in FIGURES 3, 6 and 11, is mounted for vertical adjustment on a trigger microswitch support 218 secured to deck plate 54 and mechanically actuated by trigger microswitch rod 222. Trigger microswitch is also a normally open microswitch having an adjustable rod tip 224 located immediately to the rear of heel pin 50 approximately /a" above the heel pin base 226 so as to cause microswitch -60 to close electrically when depressed downwardly by last 32.

As shown in FIGURE 1, the various components of pneumatic power station 200 are mounted within the frame 56 of the machine above a compartment housing the electrical control equipment 220. As schematically illustrated in FIGURE 11, main switch 62 and indicator light 63 are connected to a suitable electrical source of volts, -60 cycle, AC which is supplied through fuse cutouts 228 to terminals 232 and 234 mounted on a shelf 236 supported by frame 56 of the machine in the manner shown in FIGURE 1. Also mounted on shelf 236 is timer assembly 238, which includes a timer motor and adjustable multiple cam drive 240 which operates timer cam and associated microswitch 242, clamp cam and associated microswitch 244, and air blast cam and associated microswitch 246. Timer assembly 238 actuates the associated microswitches 242, 244 and 246 on a continuous cycle rate of approximately 4 seconds per cycle, as outlined in the diagram of FIGURE 12.

As illustrated in FIGURES 1, and 11, pneumatic power station 200, which is located within the supporting frame 56 of the machine and connected to a supply of compressed air 230 of about 80-100 pounds per square inch gage through suitable pneumatic circuit interconnections, includes: an air cylinder 90 with reciprocating piston 91, an adjustable air flow regulator 252, a normally open cylinder control valve 254, a normally closed cylinder control valve 256, a normally closed thruway electric solenoid valve 258 whose actuating solenoid 260 is electrically interconnected with microswitch 244 in the manner illustrated in FIGURE 11, as well as a normally closed two-way solenoid valve 262 whose solenoid 264 is electrically actuated by air blast microswitch 246.

SEQUENCE OF OPERATION With reference to the apparatus illustrated in FIG- URES 1 thru 9, main switch 62 is first closed by the operator which energizes indicator light 63 and terminals 232 and 23 4 beyond fuse cut outs 228. Then a lasted shoe 10 mounted on last 30 is presented to the delasting station 100 of the machine. The heel portion 32 of the last contains a mating thimble 34 which is slipped over the heel pin 50 in the manner illustrated in FIGURES 2 and 11. The heel portion 32 of the last 30 contacts the load sensing actuating rod 212 and deflects the rod tip 214 downwardly as pin 50 enters thimble 34, which serves to actuate microswitch 58. When the heel portion 32 of last 30 is fully seated on the heel pin 50, microswitch 60 is actuated by the deflection of trigger microswitch actuating rod tip 224.

As schematically illustrated in FIGURE 11, actuating microswitches 58 and 60 energize timer motor 240 and its associated cam drive closing timer microswitch 242 to actuate relay 24 8 which also energizes relay 250. Timer assembly motor 240 also actuates microswitches 244 and 246 through its cam drive in the sequence diagrammatically illustrated in FIGURE 12. Actuating microswitch 244 energizes solenoid 260 of clamp solenoid valve 258, permitting a supply of compressed air to actuate cylinder control valves 254 and 256, which in turn operate pneumatic cylinder 90, as shown in FIGURE 10. Flow control valve 250, between cylinder control valve 254- and cylinder 90, can be adjusted to control the rate of operation of cylinder 90.

Operation of pneumatic cylinder 90 advances piston 91 outwardly moving the associated crosshead bar 92 and interconnecting push rods 94 and 96 upwardly which cause arms 68 and 70 of the left and right clamp assemblies 64 and 66 to pivot about pins 108 and 110 and close against the sides of the lasted shoe It in the manner illustrated in FIGURES 3, 4 and 5. As the opposing clamping assemblies 64 and 66 move transversely from a retracted position toward each other, rear pressure blocks 184, 186, 188 and 190 as well as front pressure blocks 150, 152, 154 and 156 press the associated front and rear pads 72, 74, 76 and 78 against the contoured sides of the shoe under the sole 12 and heel 14. The interconnecting hinges of each clamp assembly permit an equal distribution of pressure among all of the pressure blocks so that when the pressure pads are forced against the side of the lasted shoe, each pad will assume a position that substantially conforms with the contour of the shoe side regardless of length or width of the shoe.

After the left and right clamp mechanism 64 and 66 have been pressed against the sides of the shoe, microswitch 246 actuates solenoid 264 to open blast solenoid valve 262 and permit an unreduced supply of compressed air to pass through the tubular heel pin 50. An interconnecting air passageway 36 leading from the top of the last heel thimble 34 to the bottom surface of the last 30 permits the air being ejected by the tubular heel pin 50 to enter the interior of the lasted shoe in a manner more fully described in the disclosure of the aforementioned patents.

While specific reference will be made hereinafter to the utilization of .an adhesive material in the manufacture and assembly of footwear on a last, it should be understood that the present invention is not limited in any way to the type of insole securing means employed since it is possible to utilize a conventional fastener during the lasting operation as long as it is removed prior to the delasting sequence being performed by the apparatus disclosed herein.

In the past, a charge of compressed air interposed between the foot contacting surface of a lasted shoe and the bottom surface of the last could escape to atmosphere due to the flexural expansion of the shoe sides away from the last causing a substantial reduction of pressure within the shoe interior. By exerting an external pressure against the exterior sides of a lasted shoe, lateral expansion of the shoe is reduced to restrict escape of the compressed air from between sides of the lasted shoe and related side portions of the last. While the left and right front pad assemblies 136 and 138 are exerting a constrictive pressure against the exterior sides of the lasted shoe, the build-up of interior air pressure against the foot contacting surface of the shoe continues until the heel portion of shoe 1% is urged upwardly relative to the last heel 32. In order to prevent any loss of internal pressure during this stage of the delasting operation, the left and right rear pad assemblies 206 and 268 continue to press inwardly against the exterior sides of the lasted shoe 10 while rotating upwardly with the heel portion 22 of shoe in the manner illustrated in FIGURE 6.

In effect, the pad assemblies form a seal between the sides of the lasted shoe and last, however it is not essential that the seal be complete. It is sufiicient if the pad assemblies restrict escape of the air to the degree such that the pneumatic pressure between the heel of the shoe and the last is great enough to cause separation of the shoe and last.

Micro-switches 244 and 246 are then opened in accordance with the sequence of operation illustrated in FIGURE 12. Valves 258 and 262 close, terminating the internal air blast and retracting the clamping mechanisms 64 and 66 to a remote position away from the delasted shoe. Micro-switch 242 is then opened by timer motor 240 which causes relay 248 to open. However, relay 250 cannot open as long as the electrical circuit controlled micro-switch 58 is kept electrically closed by the actuator rod 212, as illustrated in FIGURE 11. Until the last 30 has been completely removed from heel pin 55, the delasting cycle cannot be reinitiated, even though trigger micro-switch 61 may be repeatedly actuated.

After the operator breaks the last and removes the delasted shoe, removal of last 30 from pin 50 opens the load sensing micro-switch 58 and unlatches the relay 256 interlock which resets the control unit 229 to automatically function whenever another lasted shoe is loaded into the delasting station 100.

What is claimed is:

1. An improved method for separating footwear from a last by exerting fluid pressure therebetween comprising the step of reducing loss of fluid pressure by leakage between the last and footwear during separation thereof.

. 2. An improved method for assisting in the removal of footwear from a last by exerting fluid pressure therebetween comprising the step of constraining said footwear against said last to reduce loss of fluid pressure by leakage therebetween.

3. An improved method for removing footwear from a last by exerting fluid pressure therebetween comprising the step of restraining said footwear from expanding during removal thereof from said last to reduce loss of fluid pressure by leakage therebetween.

4. A method of removing a shoe or the like from a last comprising the steps of applying external pressure to portions of the shoe to constrain the same against the last and introducing a fluid charge between the last and a corresponding interior portion of the shoe to separate the same.

5. A method of removing a shoe or the like from a last comprising the steps of applying pressure to portions of the shoe causing said portions to engage the last, introducing a fluid charge between the bottom portion of the last and a corresponding bottom portion of the shoe to separate the same, relieving the pressure applied to said portions of the shoe, and entirely removing the shoe from the last.

6. A method of detaching a shoe or the like from a last comprising the steps of applying pressure to portions of the shoe causing said portions to engage the last to form a seal in effect and introducing a fluid charge between a bottom portion of the last and a corresponding bottom portion of the shoe to separate the same.

7. A method of removing a shoe or the like from a last comprising the steps of applying mechanical pressure to side portions of the shoe to cause said side portions to engage the last to form a seal in effect and introducing a fluid charge between a bottom portion of the last and a corresponding bottom portion of the shoe to separate said bottom portions.

8. A method of removing a shoe or the like from a last comprising the steps of applying pressure to side portions of the shoe to cause said portions to engage the last to form a seal in effect and introducing a fluid charge between the heel portion of the shoe and the corresponding bottom portion of the last to separate said heel and bottom portions.

9. A method of detaching and removing a shoe or the like from a last comprising the steps of applying mechanical pressure to external side portions of the shoe causing said portions to engage the last to form a seal in effect, introducing a fluid charge between the heel portion of the shoe and the corresponding bottom portion of the last to detach said corresponding portions, relieving the pressure on the side portions of the shoe and entirely removing the shoe from the last.

10. A method of removing a shoe or the like from a last the steps comprising applying pressure to opposite side portions of the shoe to cause said portions to engage the last and introducing a fluid charge between a bottom portion of the last and a corresponding bottom portion of the shoe to separate said bottom portions.

11. A method of removing a shoe or the like from a last the steps comprising applying pressure to opposite side portions of the shoe to in effect form a seal between said side portions of the shoe and corresponding portions of the last and introducing a charge of fluid pressure between the rear bottom portion of the last and the corresponding heel potrion of the shoe to separate the same.

12. A method of removing a shoe or the like from a last the steps comprising applying pressure pads to opposite side portions of the shoe to cause said side portions of the shoe to tightly engage the last to form a seal in effect, introducing a fluid charge between the heel portion of the shoe and the corresponding bottom portion of the last, removing said pressure pads from the side portions of the shoe to break the seal, and entirely removing the shoe from the last.

13. A method of removing a shoe or the like from a last the steps comprising applying pressure pads to opposite side portions of the shoe causing said side portions to engage the last to form a seal in effect between the side portions of the shoe and a corresponding portion of the last, introducing a fluid charge between the bottom portion of the last and a corresponding bottom portion of the shoe to separate said bottom portions.

14. An improved method of removing a shoe or the like from a last by fluid pressure therebetween comprising the step of applying pressure pads on opposite sides of the shoe to constrict the shoe against the last to reduce loss of fluid pressure between the shoe and the last to cause separation of the shoe and last.

15. An improved method of separating a shoe or the like from a last by fluid pressure exerted between the shoe and last comprising the step of reducing loss of fluid pressure between the shoe and last prior to and during separation of the shoe and last by fluid pressure.

16. An improved method of separating a shoe from a last comprising the steps of restraining the shoe on the last against expansion, introducing a fluid charge between the bottom of the last and the shoe to separate the same and continuing to restrain the shoe against the last during separation.

References Cited UNITED STATES PATENTS 2,093,435 9/1937 Grush 1215.1 3,091,787 6/1963 Hawkes l2-15.1 3,106,730 10/1963 Reid et al. l2142 3,107,324 lO/1963 Reid et a1. 12-l5.1

PATRICK D. LAWSON, Prinuuy Examiner. 

